Oily Water Separator Service

Bilge oily water separators, also known as oily water separators (OWS), are on-board treatment systems designed to remove the oil from the vessel bilgewater (oil water separator) prior to its discharge.

The bilgewater is a mixture of water, oily fluids, lubricants and grease, cleaning fluids, and other wastes that accumulate in the lowest part of a vessel from a variety of sources, including engines (and other parts of the propulsion system), piping, and other mechanical and operational sources found throughout the machinery space of a vessel.

Bilge spaces are periodically pumped out, and the accumulated bilgewater is transferred into a holding tank. The bilgewater then can be managed by either retaining it onboard in the holding tank and later discharging it to a reception facility onshore or treating it onboard with a bilge separator.

The advancements in bilge oily water separator technologies in recent years have helped improve the effectiveness of oily bilgewater treatment.

Need your Oily Water Separator Serviced? Separator Spares & Equipment is a reliable solution for your oily water separator service needs. We offer a full range of bilge oily water separator service including servicing the oil content monitors. We provide equipment, consumables, spare parts, and services for coalescing filter OWS, centrifugal OWS, and oily content monitors.

Gravity Separation:

Early oily water separators were mainly of the gravity separation type that employs plate or filter coalescing technology to separate oil and water. The bilge water is usually heated gently to improve separation, with the oil gradually settling out above the water content. The oil is then pumped to the holding tank, and the water is discharged to the sea after passing through the oil content monitor. Without further refinements, gravity separators can have difficulty meeting the 15-ppm standard, especially when the bilge water contains emulsified oils that do not separate easily.

Centrifugal Separator:

Centrifugal separators also work using the different densities of oil and water but with the centrifuge greatly multiplying the gravity effect as the centrifuge accelerates. This oily water separator is more efficient and can generally deal with emulsified oils. They run continuously without significant man-hours for operation and supervision and handle varying bilgewater composition, solids loading, and oil content, as well as the rolling and pitching motion of the ship.

Many crew members are familiar with this type of technology which is also used to treat fuel and lubrication oils onboard vessels. They are more compact than gravity-type separators but have the disadvantage of requiring power to operate the centrifuge. Because of their moving parts, they often have a higher maintenance requirement.

Centrifugal oily water separators manufactured by GEA Westfalia Separator are an excellent option for new builds and retrofit. The GEA Westfalia BilgeMaster oily water separator modules are assembled to form a complete unit and can also be supplied as individual modules upon request. This means that the system can be customized to meet the local circumstances in an optimum manner, even in restricted spaces. This makes it an excellent option for replacing old Alfa Laval PureBilge oily water separators. To learn more, visit our GEA Westfalia BilgeMaster Oily Water Separator webpage.

Absorption and Adsorption:

Absorption and adsorption are both physicochemical sorption processes that can be used to separate oil from bilgewater. Absorption is the incorporation of a substance from one physical state into another physical state (a liquid absorbed by a solid). Adsorption is the physical adherence or bonding of molecules onto the surface of another phase (reagents adsorbed from water only a solid surface).

Bilgewater is pumped through the sorption media in a reactor vessel or contactor for both processes, and the oil is removed from the media. Once the capacity of the sorption media is exhausted, the reactor or contactor is removed from service, and the media is replaced. The spent media is an oily solid waste residual for all sorption processes. Certain spent media can be regenerated aboard ships, while others may be regenerated or disposed of onshore.

Organoclay is widely used to absorb oil from water. When organoclays are placed into water containing mechanically emulsified oil, greases, and large chlorinated hydrocarbons, the organophilic clay will remove these compounds by a partitioning process. Therefore, organoclay can be used to remove emulsified oil and grease and other sparingly soluble organics. Disposal options for spent media are cement kilns, landfills, bioremediation through land farming, cement encapsulation, or incineration.

BOSS Oily Water Separators primarily utilize this technology.  In their second stage of the BOSS oily water separators, they use organoclay as the standard for their bulk media. This media has the advantage of being efficient and long-lasting. The bulk organoclay media is the lowest cost alternative for removing emulsions. Activated carbon can also be an option but does not last as long. To learn more, visit our BOSS Oily Water Separator webpage.

Flocculation and Coagulation:

Flocculation and coagulation make use of an emulsion-breaking chemical to treat emulsions after any free oil has been separated. The chemical breaks down the emulsion, and the released oil comes together to form flocks which can then be skimmed off, leaving the remaining water to go through further filtration stages. This method produces large amounts of sludge and requires an outlay on the chemical reagent.

Biological:

Biological treatment employs micro bacteria in a bioreactor to literally consume the organic chemicals in the oil, converting it to carbon dioxide and water. It is a slow but effective treatment for oil and emulsions as well as also removing some of the other solvents often found in the oily bilge water. Capital outlay can be high, but operating costs are low. Care must be taken to avoid overload on the microorganisms and maintaining the operating temperature within the safe range to avoid destroying them.

Filtration:

Membrane technology, ultrafine filtration, and reverse osmosis are all physical means of preventing oil and other large molecules from remaining with the water that can pass through the filter barrier. They are efficient but require attention to avoid the blocking of the filter or membrane.

Compass Water Solutions’ Ultra-Sep Oily Water Separators utilize this technology.  In their second stage of Ultra-Sep, they utilize their SPIR-O-LATOR® technology, which provides a positive, physical barrier to break emulsions and provides continuous less than 15-ppm (or 5-ppm if required) discharge.  To learn more, visit our Compass Ultra-Sep Oily Water Separator webpage.

In some situations where space is limited, BOSS’ MiniBOSS Oily Water Separator system is an excellent option.  The MiniBOSS oily water separator system is a compact IMO MEPC 107(49) certified system utilizing easy to change, disposable sediment and oil removal cartridge filters.  It has a small footprint and is designed to be wall-mounted.  It is designed to meet the discharge requirements on the smaller vessels with a small amount of bilge water and a small amount of oil. To learn more, visit our MiniBOSS Oily Water Separator webpage.

Need your Oily Water Separator Serviced? Separator Spares & Equipment is a reliable solution for your oily water separator service needs. We offer a full range of services for bilge oily water separators and oil content monitors. We are your link to IMO MEPC 107(49) compliance.